Dental articulator.



Nm 870,909, PATBNTBD Nov. 12, 1907.

G. B. SNOW.

DENTAL ARTIGULATOR. u PLIoATIoN HLM) AUG. a, 190e.

mum

UNIT

It STATES PATENT OFFICE.

BUFFALO, NEW YORK.

DENTAL ARTIGULAT'OR.

Specification of Letters Patent.

Patented Nov. 12, 1907.

Application filed August ii. 1906. Serial No. 329.691.

To all lwhom it may concern.

Be it known that I, Guorior; B. SNow, a citizen ofthe United States, residing at Buffalo, in the county of Erie and State of New York, have invented a new and useful Improvement in Dental Articulators, of which -the following is a specification.

My invention relates to dental articulators and more particularly 'to improvements in articulators, which make the operation of the same conform to the recent discoveries in dental science as to the true nature of the bite.

v .The object of my invention is to provide a simple means whereby the dentist will be ablc tov ascertain the inclination of the bito-paths of the condyles, and an articulator with which these conditions, together` with others existing in the mouth of the patient may be convcniently and accurately duplicated.

1n the drawings herewith, which show a' typical form v `for carrying out my invention, in which like characters of reference indicate corresponding pa1ts,-Figu1'e l isa planview; Fig. 2 is ai rear elevation; Fig. 3 is a side ele? fvation, one of the bearing supports being cut away to show the-link; Fig. 4 is a side elevation on aslightly reduced scale showing my method ot' obtaining the link inclination; Fig. 5 is'a perspective of one of thc links; Fig. 'isa perspective of one of my gage pins. In Figs. [t to 4 I have shown the plaster models and trial plates in The articulator consists of an upper section 7 and a lower section 2. The wire loop 1 which supports the lower plaster model 21 is held in and is adjustable vertically in the sleeves 3 in the section 2, and is fastened by the set screws 4. A similar wire-loop 5 supports 'the upper plaster model 20, and slides horizontally in the lugs upon the upper section 7, and is secured, 'when correctly placed, by the set screws 6. The lower section 2 has its ends bent upwardly at right angles to form thebearingfsuppoits 8, S. The upper section 7 is connected to these bearing-supports byrneans of back wardly extending ends 9, which are transversely bored i `and slotted to form clamping-bearings by means of the clamping-screws l0. Pivot pins 14 are threaded through the bearing supports 8 of the lower section 2 and have reduced non-threaded ends toiorm pivot bearings and at their outer ends are provided as shown withlcylindrical bearing surfaces adapted for the atfaces-olf the extensions 9 and the inner faces of the snpports 8 are placed the pivot links 11. These links, as

clearlyshown in Fig. 5, have cylindrical shanks l2 ,which enter the clamp bearings 9 and which are clamped against rotation -by the screws 10. These links have slots' 13, and the axes of the Shanks 12 are in l center with the centers of the rear ends of the said slots 13. clearly shown in Figs. 1` and 5 upon a radius equal to the distance between the supports 8.

Aspring 15 has its ends inserted in axial drill-holes in the inner ends of the lugs 12 of the links 13, and is formed with a central forward loop and two adjacent rearward loops, llying in substantially the same plane. I t normally tends to take the position shown in broken outline in Fig. 1. Secured to the lower section 2 is a stud 16, having a neck which is capable of removably engaging the central loop of'the spring 15 when forced forwardly and onwardly. When the spring is held by the stud 16 its ends te'nd to force the upper section 7 orwardly until the pivots 14 rest against the rear end-walls of the slots 13 in the links 11, when they are central with the Shanks 12. Y

Threaded to a lug on the lower section 2 is an adjustable screw 17, which basa broad flat head and whichis locked by a check-nut, 18; Projecting downwardly which is secured to or integral with the upper section 7. The screw 17 and the lug 19 coperate to limit the bite as established. l

20 is the upper plaster model and 21 the lower plaster model secured respectively to the upper and lower loops in the usual manner; and 22 and 23 are respectively the upper and lower trial plates. i l.

By reason of the inclination of the lines of condyle displacement, the movement of the lower jaw, when it is thrust forwards, is not horizontal, but forwards and downwards. `nd when the trial plates 22 and 23, having flat articulating surfaces, are placed in the mouth, these surfaces will, when the lower jaw is when the lower jaw is thrust forwards and raised these surfaces will only touch in front, and will be more or less widely separated at the rear; as shown in Fig. 4. My gage pins, which are intended to be'used in pairs, (see Fig. 6), are devised to measure the amount of separation of the articulating surfaces of the trial plates under this condition, and so to enable the dentist to ascertain the angle of inclination of the condyle displacement for the case in hand.

The pin 26, which is designed to penetrate the wax of the upper trial plate, as shown in Fig. 4, is mounted upon a flat plate 24, which has spurs 25, which penetrate the surface of the lower trial plate, and so secure the fixture thereto. This is shown 'in situ in Fig. 4, and of normal size in Fig. 6.

Having thus described the parts of the apparatus,

and directly over the head o1 the screw 17 is a lug 19,A

raised normally, coincide as shown in Fig. 3. But

The outer faces of these links are curved, asv

its operation is as follows: The trial plates 22 and 23 4. )The .platesare-thenre-inserted themouth of the patient, with the gage pinsiin place. The Apatient withthe plates-separated, ex tends the lower jaw forwardly and then bites the'plates together',- which establishes two impression prints in tlieplate22 by the pins 26. The plates'are their put in place and adjusted in the articulator` by.the use of the fac-e bow Aan'd the usual marks on the'plates .whichl f the normal-'or first bite,' the gage pins being,

for the. time being, removed. The` spring 41 5 being then released, the screws loosened and the link s 1 1 turned downwardly andthe gage pins replaced; the

. 'upper-.sectionoi the 'articulat'or is moved backwards until the points ofthe gage pins' 26 are 'received into the impressionsthey'have previously I nade inthe suriceoi the'trial plate 22. A The links 11 are then turned upwards until the pins 26 have entered the 'impressionsin` theftrial-'plate 22 totheir `full depth, when the `u :l'e'ws 10 are tightened to secure the links 11 and' the -Cent'ral loop.. of thespring 15 is again engaged with' 'the stud v16.` The movementso the. articulato'r joints' in 'the-elm 1s win than be identical was mss-@ofthe 'condyles of the jaw in their bite-paths;

It will be 4seen that'the pins 26 registerr not only the' amount of separation of the trial;plates by the forward thrust'of the condyle, but also the distance through whichfthe thrust is made, and that the conditions of condyle displacement in the patient are accurately imitated. ,Since-the position of the linksll governs the movement between the channel plates the articular rotation established Will be as above explained.

A As I am not aware that any device has heretofore been produced for-registering the amount oi forward move ment, and the-separation of dental trial-plates in the mannerhere shownf, I :do not-wish confine myself- .to the vprecise'.construction I have described; for lit is obvious that any form can be given tothe device .which would vbe capable of being impressed intothe'- wax, of which'the 'articulating ridges of the trial plates are composed, It will, of course; be understood that the pivots 14, with relation' to theposition of thetral 'plates as adjusted, will lie' in thel axis of the condyles.

Having thus described my'invention and its method of operation, what I vc lairn is:

1.` A dental ar'ticnlator.-v comprising upper and lower" sections; joint pins inthe lower section, slotted `links in terposed between the-two ssctions'to completethel joints,

`and gripping sockets in the upper section'l into which said links are joixrnaled. I

iL-.In a ydental articulatory the combination twosections jointed together by means of slotted connections. of-a spring having both ends xed in sockets axial with the jointsof. one of said sections and detachably'secured at an intermediate p oi'nt to the other of said sections.

3. 'A gage pin for ascertaining theinclination of the condyle path, havingy projections above and below. adapted to penetrate the ar-ticnlatingsurfaces' oi! the upper and 

